1,7-Naphthalenedisulfonic acid, 4-amino-6-[[4-[(2,4-diaminophenyl)azo]phenyl]azo]-5-hydroxy-, disodium salt

2-(4-Aminophenylamino)-2-oxoacetic acid?diazo, and Benzene-1,3-diamine coupling, and then 2-(4-Aminophenylamino)-2-oxoacetic acid hydrolysis of the product to diazo, in alkaline conditions and 4-Amino-5-hydroxynaphthalene-1,7-disulfonic acid coupling.

black. Moderate soluble in water for dark purple, soluble in ethanol. In the thick of sulfur acid for green light blue, diluted is shallow brown. The dye solution to join strong hydrochloric acid for red sauce, precipitation; Add thick sodium hydroxide solution for purple.

Standard	Acid Resistance	Alkali Resistance	Light Fastness	Soaping		Water
				Fading	Stain	Fading	Stain
AATCC	5	5	3	3		4